DOI

10.5703/1288284314244

Abstract

The objective of this project was to evaluate the transport properties of concrete pavement in the state of Indiana using common testing procedures. Specifically this work evaluated the absorption of water, the absorption of deicing solutions, and electrical conductivity. A series of concrete paving mixtures were tested to provide a range of values that were typical for the state of Indiana. While similar mixture proportions were used for the mixtures in Indiana differences in the magnitude of water absorbed occurred. A series of mortars were tested to illustrate the effect of curing conditions, water to cement ratio, and paste volume. It was observed that a long duration of drying was needed to obtain equilibrium. Samples dried to a lower relative humidity showed a greater volume of water absorbed. It was observed that drying at 105C resulted in substantial anomalies in water absorption, as such this method is not recommended. It was observed that when samples were tested using deicing solutions or samples were tested that were previously exposed to deicing solutions the water absorption could be influenced. The electrical conductivity work was performed as a potential method to develop the understanding of rapid test techniques for quality control. The research used a modified parallel law to relate the electrical conductivity to the pore volume, pore solution conductivity and the tortuosity through the pore network. The influence water addition was able to be determined using electrical conductivity. In addition, the pore solution was observed to be approximately linearly related to the degree of hydration. It is critical that a correction be applied to samples tested at different temperatures. An activation energy of conduction was observed that was approximately 10 kL/mol irrespective of water to cement ratio. In addition to the measurement of transport properties, the relative humidity was assessed for concrete exposed to different exposure conditions. The samples considered in this investigation included a sample stored at 50% relative humidity, covered concrete, a concrete with an exposed vertical surface, a concrete on a drainable base, a concrete on a non-drainable base, and concrete that was submerged. The samples showed that for practical field samples the relative humidity in the concrete was always above 80% for the samples tested. The samples that were exposed to precipitation events demonstrated higher relative humidities.